First responders and chemical workers must be able to function in environments where chemical hazards are present. Industrial workers need protection against hazardous chemicals used in the workplace and HAZMAT personnel need respiratory protection when dealing with chemical spills, methamphetamine labs, and other cleanup operations. In the event of exposure to chemical vapors/gases from an industrial or environmental accident, respiratory protection is particularly important. The modern gas mask has a vapor tight polymer face piece that is equipped with windows and a cartridge containing activated carbon that filters the inhaled air. Most modern masks have a check valve so that exhaled air passes out of the valve rather than back through the activated carbon cartridge. As air is inhaled through the activated carbon in the cartridge, hazardous contaminants physically adsorb on the carbon surface, and because activated carbons can have surface areas of 1000 m2/g or greater, reasonably large amounts of contaminants can be removed with a single cartridge. To date, no simple technology has been developed that allows the user to determine if the chemical protection capability of a respirator cartridge has been reduced by exposure during storage, or by saturation with gases while it is in use. What is needed is a simple device that indicates the expiration of a respirator cartridge. This device would be a permanent part of a respirator cartridge integrated into the cartridge during manufacturing. Since the device is incorporated into the respirator cartridge during manufacture, the indicating device can be certified by NIOSH, and thus used by first responders. TDA proposes to develop an end of service life indicator (ESLI) that can be incorporated into a first responder chemical hazard respirator cartridge. PUBLIC HEALTH RELEVANCE: There is no simple technology has been developed that allows the first responder to determine if the chemical protection capability of a respirator cartridge has been reduced by exposure during storage, or by saturation with gases while it is in use. What is needed is a simple device that indicates the expiration of a respirator cartridge. This device would be a permanent part of a respirator cartridge integrated into the cartridge during manufacturing. Since the device is incorporated into the respirator cartridge during manufacture, the indicating device can be certified by NIOSH, and thus used by first responders. TDA proposes to develop an end of service life indicator (ESLI) that can be incorporated into a first responder chemical hazard respirator cartridge. In order to accomplish these goals in the proposed Phase I project, TDA proposes to build a test apparatus that permits us to generate precise and verifiable concentrations of challenge agents for testing the indicator, prepare indicator test strips on a porous support material, test indicator sensitivity using a variety of challenge vapors at different concentrations, temperatures, and relative humidities, in collaboration with our manufacturing partner, construct and test a prototype device, and perform an engineering analysis to estimate the costs of manufacturing commercial units.